I’m trying to print some parts for a friend. He provided the STL files, and I sliced them in Cura just as I’ve done with all the other stuff I’ve printed.
5-10 minutes into printing these parts (NOTE - there’s nothing interesting about these parts, so I don’t think it has anything to do with the parts themselves; links to the parts on Thingiverse below), when the machine is still on the initial layer, it stops feeding filament. I’ve opened the extruder while printing (after the failure) and confirmed it’s still turning, and I’ve also manually pushed filament through, so the nozzle isn’t clogged. Also, when the failure happens, the machine is doing the infill for the initial layer, so it’s not doing a lot of retracting/feeding/retracting/feeding (or at least I don’t see why it would be).
The filament looks like it’s getting chewed up by the extruder gear to the point that the gear can no longer grab it.
Although this is my first 3DP, I have printed many things with it and the Snapmaker-provided PLA, and this is the first time this has happened. I’ve restarted this print several times - same result each time. I’ve also:
Re-leveled the bed (several times)
Tried the included print bed as well as a glass bed and glue stick (same result)
Adjusted the Z-height just like a normally do (where the card is under tension when pulled and bends when pushed)
Dehydrated the filament in my food dehydrator for several hours at about 120F (second time I’ve done this)
At this point, I’ve ordered some different PLAs on Amazon to see if they make a difference. While I’m waiting for them, figured I’d post here to see what you all have to say.
Besides the PLA quality, and given my comments above, is there anything else you can think of that could be causing this problem? Does PLA quality degrade with each subsequent dehydration? Is it possible the spring pressure on the extruder wheel is softening up with use and needs to be adjusted tighter (if that’s even possible, which it looks like it isn’t)?
Its unlikely to be due to the spring on the extruder wheel as this would make it less likely to grind the filament as you mentioned was happening.
Perhaps you are printing at too low a temperature? Are you using the same PLA at the same temperatures that youve had successful prints in the past on your SM2.0?
What are your retraction settings?
Is there tension on your filament line being fed into the extruder?
Have you tried increasing your z-offset by 0.1mm? Sometimes printing too close to the bed can cause this issue.
But I would agree that printing too close is most likely culprit.
It doesn’t take much to block the hole and once there’s some back pressure on the filament and the feed wheel is still turning then it grinds the filament and once it does it just won’t feed. Older filament may also be more brittle and more susceptible to this.
Also raising nozzle temp 5 or 10 degrees wouldn’t hurt to try. It may not be flowing as easily as it should and that would cause it to be pushing too hard and therefore grinding filament.
Also, are you calibrating more than between bed/toolhead changes?
Some people think this makes it more accurate, but I feel like you’re introducing one more variable. Use that as your reference point and then adjust from there.
Same issue today. After printing many things today first time problems first / secound layer with infill. No pla on the printing bed, raised z-offset several times but problem came several times. Pushing filament through the nozzle with no problem. Leveled the bed with 10 min at 60 degrees. Opening the printing head, the filament was grinded a bit, so i also thougt about the pushing pressure on the filament and that i have to adjust, this. Remember a post on facebook or anywhere that this pressure can be adjusted, but in this case???
OK. Try higher temperature (but always used the same profile…). Another thing i read in another post is to change the nozzle - i think i will try that too…
Problem is the feed mechanism. I have had this same issue on another printer.
Once the flex filament gets into the heated nozzle and starts to melt it raises the feed resistance and the current design feeder can not handel this and it either just rubes at the filament and stops pushing or as in my case it pushes it into a knot below the drive head.
I fixed this on my other printer by designing a feed tube insert that went into the current feed head, making it tighter, that i could push closer to the feed mechanism. I did this top and bottom of the feed mechanism. Now it is supported just before the top and after the bottom of the feed drive. Very little space unsupported for it to bend. Problem solved. I have not looked to see if this will work with snapmaker yet. They may need to redesign the print head to handel flexible filament.
Speed of retraction and it’s distance. Single extruder gear is a very small diameter, smaller then standard mk8 gear. On prints with many retractions, it diggs into the filament on the same spot.
Rrdusing the speed drastically and optimizing slice for min retractions helped me.